/*
 *   Copyright 2012, Thomas Kerber
 *
 *   Licensed under the Apache License, Version 2.0 (the "License");
 *   you may not use this file except in compliance with the License.
 *   You may obtain a copy of the License at
 *
 *       http://www.apache.org/licenses/LICENSE-2.0
 *
 *   Unless required by applicable law or agreed to in writing, software
 *   distributed under the License is distributed on an "AS IS" BASIS,
 *   WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 *   See the License for the specific language governing permissions and
 *   limitations under the License.
 */
package milk.jpatch.classLevel;

import java.util.ArrayList;
import java.util.List;

import milk.jpatch.CPoolMap;
import milk.jpatch.Patch;
import milk.jpatch.Util;

import org.apache.bcel.classfile.Method;

/**
 * Patches a method.
 * @author Thomas Kerber
 * @version 1.0.0
 */
public abstract class MethodPatch implements Patch<List<Method>>{
    
    private static final long serialVersionUID = -4266370223028893008L;
    
    /**
     * The methods identifier. Consists of name and argument types.
     * (NOT return type)
     */
    protected final String identifier;
    
    /**
     * Creates.
     * @param identifier The methods identifier. Consists of name and argument
     * types. (NOT return type)
     */
    protected MethodPatch(String identifier){
        this.identifier = identifier;
    }
    
    /**
     * 
     * @return The methods identifier. Consists of name and argument types.
     * (NOT return type)
     */
    public String getIdentifier(){
        return identifier;
    }
    
    @Override
    public List<Method> patch(List<Method> methods, CPoolMap map){
        methods = new ArrayList<Method>(methods);
        // Find preexisting method.
        for(int i = 0; i < methods.size(); i++){
            if(Util.getMethodIdentifier(methods.get(i)).equals(identifier)){
                Method newMethod = patch(methods.get(i), map);
                if(newMethod == null)
                    methods.remove(i);
                else
                    methods.set(i, newMethod);
                return methods;
            }
        }
        // No preexisting field found.
        Method newMethod = patch((Method)null, map);
        if(newMethod != null)
            methods.add(newMethod);
        return methods;
    }
    
    /**
     * Patches the method.
     * @param m The method to patch.
     * @param map The cpool map.
     * @return The patched method.
     */
    public abstract Method patch(Method m, CPoolMap map);
    
}
